Hearing devices are typically small ear-level devices used to improve the hearing capability of hearing impaired people. This is achieved by picking up the surrounding sound with a microphone of a hearing device, processing the microphone signal thereby taking into account the hearing impairment of the user of the hearing device and providing the processed sound signal into an ear canal of the user via a miniature loudspeaker, commonly referred to as a receiver.
In particular, relating to in-the-ear (ITE) hearing devices, the problem exists that in an acoustic output or rather acoustic output opening towards the inner ear of the user, contamination can occur, in particular caused by cerumen. Also the acoustic input of a hearing device is exposed to dirt. In the context of the present invention both microphones and receivers are denoted as transducers.
Transducer protection systems used to protect against entrance of cerumen are known. The working principle of these systems is a mechanical grid (a fabric, molded structure, porous membrane) that covers the acoustic output opening of a hearing device. In the state of the art as disclosed in EP 0 310 866 B1, measures are known to prevent or at least to reduce essentially the contamination by cerumen of an in-the-ear (ITE) hearing device by using a membrane as ear piece protection. A cerumen protection system based on a microporous membrane is disclosed that is mounted into a cap which can be fixed onto the output opening of the ITE or earmold.
Document U.S. Pat. No. 6,891,956 B2 describes a membrane-based protection device for an ITE, wherein the membrane is removable for cleaning and arranged basically in a parallel fashion to the axis of the ear canal. Document U.S. Pat. No. 7,751,579 B2 describes a membrane-based barrier used to protect the sound exit or entrance of an acoustic device. This barrier is formed by a non-rigid, non-tensioned film that basically reradiates sound from the acoustic device. Document U.S. Pat. No. 7,793,756 describes a replaceable protection membrane for hearing devices based on an elastomeric foil of constant thickness that is mounted onto a plastic carrier ring by bonding or welding.
Document DE 3 736 591 A1 describes a labyrinth-like structure for a cerumen filter involving radial wires that are fixed in the center and fixed to the outer edge like spokes in a wheel. Document WO 93/12626 describes a cerumen protection patch that can be fixed onto the hearing device shell. This patch has a central porous part covering the sound exit consisting of an open porous foam or a non-woven textile. Document U.S. Pat. No. 5,099,947 describes a coil-like wax filter that can be inserted into the sound exit of a hearing device and is interference-fitted. This coil comprises a wire wound in a spiral path such as to cover a large area of the sound exit. This system needs to be removed for cleaning by using tweezers or any other tool suitably for removing. Document WO 2005/096 671 A1 describes a cerumen guard for a hearing device comprising a chamber adapted to accommodate various different filters depending on the respective user needs. This arrangement serves to block cerumen from entering into the receiver. Further solutions are proposed in U.S. Pat. No. 6,671,381 B1; U.S. Pat. No. 8,019,106 B2; and US 2007/0223759 A1.
In the state of the art, problems arise in that any attempt to clean protection systems comprised by a porous filter or foam will result in that cerumen is pressed further into the pores of the filter or foam. A further problem is that cerumen and/or debris might accumulate on the surface of the device, which only can be cleaned by wiping involving the risk of damaging the membrane. Due to this, cleaning imposes a difficulty for hearing device users. Further, in the state of the art, cleaning of protection systems involves the risk of damaging thereof.
It is an object of the present invention to provide a transducer protection system and hearing device solving the problems in the state of the art.